1. Field of the Invention
This invention relates to a method for forming a wiring pattern on a wiring board, especially for mounting thereon an integrated circuit.
2. Prior Art
The wiring boards for mounting ICs are formed with a wiring pattern not only around the IC but also between IC pin insertion holes in order to efficiently form the wiring pattern. Especially, in a case that the so-called CAD system is utilized to automatically form the pattern in high density, it is required that as many as possible wiring lines be interposed between the IC pin insertion holes.
The circuits in the conventional wiring pattern, however, have all been formed by an etching method (e.g., an etched foil method). As a result, the line width of the pattern is limited to a minimum, and the number of the wiring lines between the IC pin insertion holes are also limited to one or two at the maximum.